Project

# Title Team Members TA Documents Sponsor
39 Request for Approval: Soil Moisture Controller (Pitched Project)
 First Yingyord
Isabel Alviar
Ren Yi Ooi
 Dushyant Singh Udawat design_document1.pdf
design_document2.pdf
design_document3.pdf
final_paper1.pdf
other2.pdf
other1.pdf
photo1.HEIC
presentation1.pdf
proposal1.pdf
video
This project is a pitched project idea by the U.S. Department of Agriculture’s research laboratory on campus. It would be performed in partnership with a capstone team from the Department of Agricultural and Biological Engineering.

# Problem

One of the biggest limiting factors for gains in agricultural productivity is the ability to provide sufficient moisture in the soil for the growth of crops. In particular, arid regions face the possibility of the occurrence of droughts that reduces the crop yields in dryland agriculture. To manage this issue, various water management strategies have been developed to ensure that there is sufficient water being applied over these crop lands. These irrigation systems have to provide control over the amount of water that is being applied over these crop lands such that optimal agricultural productivity is achieved while ensuring maximum water use efficiency.
Currently, the measurement of soil moisture content in pots are performed manually with individuals monitoring the moisture level based on weight, or the use of gravimetric sensors. Upon irrigation, the weight or load of the pot would be at its maximum, and due to evapotranspiration over time, this weight would be lowered. When it eventually crosses a threshold set by the sensor, irrigation of the pots would be triggered again. However, due to the many different components that make up the weight of the pot, it is difficult to measure the exact proportion of increase in plant mass to the change in soil moisture content to obtain an accurate indication of when the irrigation has to be activated. As a result, there is a need for a more precise method to measure and maintain the soil moisture conditions in these pots through the use of soil moisture sensors. These soil moisture sensors would allow for the moisture that exists in the pot to be read so that sufficient irrigation is provided for consistent moisture.

# Solution Overview

Our solution consists of a cheaper yet more effective device that provides constant moisture monitoring and water irrigation as needed. When the moisture within the substrate is below the predetermined target level, the water valve will be triggered to an extent where the moisture can be maintained at that level. In addition, the users are also allowed to check the current status of each pot, that is whether the substrate moisture is desirable, and control the target level in the pot.

We would work alongside the team of ABE students to also ensure that our solution could be scaled up for high-throughput of at least 50 plants in the future.

# Solution Components

## Subsystem 1: Irrigation Subsystem

Irrigation is the process of artificially applying controlled amounts of water to land or crops. This is done by using valves as well as a system of tubes and pumps to bring in water from pipes, canals, sprinklers, and other mean-made water sources, instead of relying on rainfall. For this project, the irrigation subsystem for each soil pot would consist of a valve that would open and close based on the moisture level measured, in order to maintain a desired set of moisture conditions for different soil and soilless substrate mixes. Irrigation is needed in a given pot if it is sensed that the moisture level falls below a certain value (for example, below 60 for fine soil). When this happens, relay switches activated by a microcontroller, such as an Arduino, will operate the irrigation valves (likely 24V) that correspond to each sensor-controlled pot, and water will flow out until the soil reaches an ideal value again.

Potential materials:
- ¾” valve:
- https://www.amazon.com/Galcon-Irrigation-Reinforced-Greenhouse-Residential/dp/B08MTQB8BX/ref=sr_1_4?crid=3RHJI5FFG6PJE&keywords=24v+irrigation+valve+3%2F4+water&qid=1675117467&sprefix=24v+irrigation+valve+3%2F4+water%2Caps%2C113&sr=8-4
- https://www.amazon.com/Beduan-Electric-Solenoid-Normally-Colsed/dp/B07YTHKHL4/ref=sr_1_3?crid=2QMUSM9AGT0L8&keywords=24v%2Birrigation%2Bvalve%2B3%2F4&qid=1675117428&sprefix=24v%2Birrigation%2Bvalve%2B3%2F4%2Caps%2C100&sr=8-3&th=1
- Tubing: https://www.amazon.com/Tubing-Flexible-Hybrid-Lightweight-10-Feet/dp/B07HF648M5/ref=sr_1_4?keywords=clear+plastic+tubing&qid=1675117678&sr=8-4
- Hose ring: https://www.amazon.com/Selizo-Including-Adjustable-Clamps-Stainless/dp/B07G9TZLRM/ref=sr_1_8?crid=1C737TN4ANA1X&keywords=hose+ring&qid=1675117705&sprefix=hose+ring%2Caps%2C114&sr=8-8

## Subsystem 2: Data Acquisition Subsystem

The data acquisition subsystem will consist of a data logger, an instrument that monitors and records changes in conditions over time. Most data loggers can accept two or more types of input, so we would program ours to take inputs such as voltage, current, temperature, etc. The data logger will ultimately communicate the need for irrigation by measuring and recording calculated factors like volumetric water content for each soil, and generating a list of plants that require irrigation. Then, this list of plants will be sent to the microcontroller that carries out the irrigation process for the relevant plants by using a pulsing I/O signal of either 0 or 5V to communicate whether or not irrigation is needed. There are many expensive existing data loggers such as the CR100, but we would want to buy or build one that is still battery-powered and effective for a cheaper price. One option that nicely interfaces with an Arduino microcontroller would be to create a data logger from scratch using a data-logging shield, coin battery, and SD card.

Potential materials:
- Data-logging shield
- https://www.amazon.com/AITRIP-Logger-Logging-Recorder-Arduino/dp/B09PDL7XM7/ref=sr_1_4?crid=13UWJYJNEUANV&keywords=data+logger+arduino&qid=1675121100&sprefix=data+logger+%2Caps%2C112&sr=8-4
- https://www.amazon.com/HiLetgo-Logging-Recorder-Logger-Arduino/dp/B00PI6TQWO/ref=sr_1_3?crid=13UWJYJNEUANV&keywords=data+logger+arduino&qid=1675121312&sprefix=data+logger+%2Caps%2C112&sr=8-3
- Coin battery for shield
- SD card
- www.adafruit.com

## Subsystem 3: User Interface Subsystem

The user interface subsystem would consist of two main components. The first component would be an LCD display that shows the current soil moisture level as detected by sensors in a percentage form (out of 100%). The second component would be a dial in the form of a potentiometer for the user to be able to tune the soil moisture level to the desired level. This desired soil moisture level can also be displayed on the LCD screen.

In order to achieve this, a customizable LCD display would be used. An Arduino Uno microcontroller can be used to interface the soil moisture sensors and potentiometer with the LCD display.
Parts needed:
- 16x2 LCD display (https://www.digikey.com/en/products/detail/newhaven-display-intl/NHD-0216BZ-FL-YBW/NHD-0216BZ-FL-YBW-ND/1701195)
- Arduino Uno R3 ATMEGA328P Eval microcontroller (https://www.digikey.com/en/products/detail/arduino/A000066/1050-1024-ND/2784006)
- 10K Ohms potentiometer (https://www.digikey.com/en/products/detail/bourns-inc/PDB12-H4301-103BF/PDB12-H4301-103BF-ND/3780664)
- Breadboard (https://www.digikey.com/en/products/detail/dfrobot/FIT0096/1738-1326-ND/7597069)

## Subsystem 4: Controller Subsystem

In order to efficiently gain the desired substrate moisture level, we decide to implement a PI controller which takes the feedback input from the moisture sensor, compares the measured value with the desired value, and triggers the water valve if the measured value is below the desired value.

The value from both the moisture sensor and user input will be sent to a differential amplifier that outputs a voltage proportional to the voltage difference, and a diode that filters only the positive voltage difference i.e. when the desired moisture level is above the current level. The filtered voltage will then be inputted to the PI controller which consists of potentiometers for tuning the controller, inverting op-amps for amplification, and capacitors for implementing the integrator circuit. The reason we do not include a derivative part is to remove the instability problem which may arise from a noisy system.

Finally, the output of the controller will be amplified and connected to a LM555 Timer chip in order to generate a PWM signal to the water valve so that the amount of water being given is sufficient to each pot. Please note that further experimentation is still needed to determine the specific parts within each component.

# Criterion for Success

- The moisture sensors should be able to detect the current level of moisture in the soil for the moisture level data to be logged and displayed on a monitor
- The system should be able to provide irrigation when the moisture level falls beyond a set threshold level
- There should be a dial that allows the user to tune the moisture level to a desired value

Automatic Piano Tuner

Joseph Babbo, Colin Wallace, Riley Woodson

Automatic Piano Tuner

Featured Project

# Automatic Piano Tuner

Team Members:

- Colin Wallace (colinpw2)

- Riley Woodson (rileycw2)

- Joseph Babbo (jbabbo2)

# Problem

Piano tuning is a time-consuming and expensive process. An average piano tuning will cost in the $100 - $200 range and a piano will have to be retuned multiple times to maintain the correct pitch. Due to the strength required to alter the piano pegs it is also something that is difficult for the less physically able to accomplish.

# Solution

We hope to bring piano tuning to the masses by creating an easy to use product which will be able to automatically tune a piano by giving the key as input alongside playing the key to get the pitch differential and automatically turning the piano pegs until they reach the correct note.

# Solution Components

## Subsystem 1 - Motor Assembly

A standard tuning pin requires 8-14 nm of torque to successfully tune. We will thus need to create a motor assembly that is able to produce enough torque to rotate standard tuning pins.

## Subsystem 2 - Frequency Detector/Tuner

The device will use a microphone to gather audio measurements. Then a microprocessor processes the audio data to detect the pitch and determine the difference from the desired frequency. This can then generate instructions for the motor; direction to turn pegs and amount to turn it by.

## Subsystem 3 - User Interface/Display Panel

A small but intuitive display and button configuration can be used for this device. It will be required for the user to set the key being played using buttons on the device and reading the output of the display. As the device will tune by itself after hearing the tone, all that is required to display is the current key and octave. A couple of buttons will suffice to be able to cycle up and down keys and octaves.

## Subsystem 4 - Replaceable Battery/Power Supply

Every commercial product should use standard replaceable batteries, or provide a way for easy charging. As we want to develop a handheld device, so that the device doesn’t have to drag power wires into the piano, we will need a rechargeable battery pack.

# Criterion For Success

The aim of the Automatic Piano Tuner is to allow the user to automatically tune piano strings based on a key input alongside playing a note. We have several goals to help us meet this aim:

- Measure pitch accurately, test against known good pitches

- Motor generates enough torque to turn the pegs on a piano

- Tuner turns correctly depending on pitch

- Easy tuning of a piano by a single untrained person

Project Videos